DE1537146A1 - Method for transmitting signals from several transmission channels - Google Patents

Description

1-A'l E ΝΤΛΝ WÄLT.B

Dr. Andreevsky
Dr.-Ing. Honke
43E6flen _r KettwlserStr. 36 1 R ^ 7 1 AR

lAmHiuolbihnhol UchtburgJ I v> O / I Ή Q

Teleloa 225802/03

^: "- Essen, August 6, 1969.

»" *. ^ - "-»> .. ■■ '■' "■ :, (29 145 / Q1-)

Patent application · ■■■■ .- .., · ■ .. Company HASLER AG . .Bern

Method for the transmission of signals several transmission channels

The invention relates to a method for transmitting signals from several transmission channels in digital form via a connection path, with the transmission time in equally long frame times and these are divided into channel times, and each specific Channel times are permanently assigned to certain transmission channels. Such methods are known and will be referred to as rhythmic time division multiplexing. Firstly, they serve to transmit telegraphic messages, the news sources and sinks being, for example, teletypewriters. They are still used for the transmission of telephony, the transmission taking place with pulse code modulation. Any news source is connected to a message sink through a transmission channel.

909844/0975

The number of sewer tents in a frame time generally corresponds to known methods the number of the transmission channels, so that a signal from each source is transmitted during a frame time. Join in nor synchronization signals, which are usually summarized in a special so-called synehron channel.

Transmission systems for carrying out the process consist of a transmitter, transmission medium and Recipient. There are systems known in which the transmitter contains an input circuit which signals on a Receives a plurality of lines and sends them to an information converter passes on, which converts the signals into a form suitable for rhythmic transmission. These Conversion generally takes place in such a way that one signal in each case, e.g. a letter in the case of telex messages, In the case of telephone messages, an instantaneous value of the voltage to be transmitted is converted into a code word, which consists of a number of digital, mostly binary steps that are transmitted one after the other.

The digital signals go from the information converter to an output unit, which handles the transmission initiated the connection route in a suitable form. The messages are processed in the recipient reverse order.

9098U / 0975

Experience has now shown that both Telegraph and telephone connections only during Really transmit messages in a fraction of the time; characters are transmitted for the rest of the time}

to which the source / show an idle state. It turns out now the "" task of using this knowledge in order to achieve the same Walking speed on the transmission path to transmit more information in digital form than it would with the known method is possible.

The transmission method according to the invention is characterized in that a plurality of seldom transmitted signals as code words with a number of steps equal to the number of steps of a channel time and a minority of frequently transmitted signals as code words with a lower one Number of steps are transmitted and that the channel time segments not used in the transmission of the short code words transmission of the additional code words Channels are used that are not assigned specific channel times. The channels whose channel times are permanently assigned main channels, the channels to which no channel times are permanently assigned, are called additional channels.

The steps of a Channel time divided into step groups. Each of the short code words is a smaller number of step groups assigned as a long code word. To recognize whether a long or a short code word is present, the

909844/0975

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first step group of each code word a corresponding. corresponding license plate included. In particular, the long code words can be used to transmit the from the sources Messages sent are used, while the short code words indicate the state or one of the states of the source in which no messages are transmitted.

As an example of a method according to the invention, a method and a system for the transmission of telex characters will first be described. The transmitter and receiver are teletyping machines that send and receive using the start-stop method; however, the transmission over the channel takes place with a rhythmic method, since fewer character elements (bits) are required for the transmission of a character, for example a letter, and the transmission reliability is higher. The 5 bits of the telex code allow the transmission of 32 characters; In addition, the characters / \ (continuous start) and β (continuous stop) must be transmitted, so at least 6 bits are required for rhythmic transmission, which corresponds to the number of steps of a long code word that is transmitted in one channel time. This channel time of 6 bits is divided into two step groups of 3 bits each.

9098 k A / 0975

The characters to be transmitted are subdivided into operational characters, their code words one, traffic signs, their Codewords two, and in sync characters whose codewords contain three step groups. At a traffic sign the first bit is always a "1", the remaining bits correspond to the television code no. 2. The first bit of a Operational character and the synchronous character is always a "0", so that it is recognized after the first bit of a code word whether it is a traffic sign or an operational or synchronization sign.

Code words for operational characters are:

<h (continuous start): 010

N (continuous stop): 011

Υ (meaning freely selectable): 001

Synchronization character _: 000 000

If a code word is now transmitted in a channel that corresponds to an operating code, or the second part of the synchronization symbol, only one step group of three bits is required for this. The second group of steps is used to transmit code words from additional channels that do not have their own channel times:; uge divided. The free groups are assigned to the additional channels in sequence . However, since it is never certain

BATH ORIGINAL

1537U8

that there is always enough transmission time available for this, either buffer memory or Backward connections to the sending participants be available to block the flow of information.

The following step groups can therefore be used in one (or two in the case of synchronization characters) channel times . be transmitted:

Traffic sign lxxxxx synchronization sign 000000 OOlyyy operating sign <ή OlOyyy

/ J Ollyyy OOlyyy

As already mentioned, the χ are arbitrary

and correspond to the teletype machine code. The y groups serve to transmit the characters of the additional channels. They can either correspond to and consist of operational symbols then from a step group of 3 bits or from traffic signs and then consist of two consecutive steps y groups.

ο ν »ι-u / Γη ν · ■; ■ - ~ ^ ~

Since the combination OOOyyy does not occur, there is at least one "1" in every channel time, except for the synchronization character, which causes this is marked. The longest string of zeros that can be formed by a sequence of two characters, results from a sequence of 100000 and Olyyy; this sequence contains 7 consecutive zeros, while the synchronization character has 8.

In Fig. 1, the block diagram of a transmitter is reproduced, such as that used for transmission of telex characters is used according to the method described.

It consists of a clock generator 1, a clock distributor 2, a main channel counter 3 and an additional channel counter 4, a control circuit 5, an input circuit with a first part 11 with η lines 11 (1) ll (n), a second part 21 with m lines 21 (1) ... 21 (m), an information converter 12, a memory with two Dividers 13 and 23 of 6 cells each and an output unit 14. The clock emits a clock signal with the bit frequency to be transmitted on the rhythmic connection path Signals. The clock distributor 2 has 6 outputs, which are labeled a ... f and on which in cyclic order the clock signals occur. At the end of cycle f, the main channel counter 3 is incremented in each case.

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BATH ORIGINAL

This has η outputs at which one after the other for the duration of a channel time, i.e. during consecutive Bars a ... f, a signal occurs. The period of the Counter 3 corresponds to a frame time. The output signals of the clock distributor 2 and the counter 3 are thus each step is marked in a frame.

The input circuit 11 is connected by the lines 6 (1) ... 6 (n-3) to the message sources not shown tied together. It contains n-3 memories, each assigned to a source and at least the last can save the recorded signal, as well as an indication of the operating status of the relevant source is located. There are also 3 more storage tanks,

11 / (n) bearing the numbers ll (n-2), 11 (n-1) /. In the memory with the number ll (n-2) is the first part of the synchronization signal, the combination 000000 is permanently inscribed (it does not need to be present at all). in the Memory 11 (n-1) the combination 001000, the second part of the synchronization signal. The purpose of memory with the number η will be explained later in connection with the synchronization of the additional channels.

Signals from clock distributor 2 and counter 3 at clock time d cause the Characters stored in the individual memories 11 (1) ... ll (n) are transmitted to the information converter 12.

909844/0975

The lines, which only transmit signals at a certain cycle time, are indicated by the letters a ... f, which refer to the transmission cycle times Clues. If the letter is in brackets, there is not a signal over the line in every channel time given.

There is no in the queried memory

finished ^ calibration before, depending on the condition of the i

Transmitter transmits either the code character corresponding to the state J ^ or the state β. The information conversion in telegraphy is a code conversion and in the simplest case consists only of adding a "1" to the first digit if it is a traffic sign, but other known conversion options can also be used, especially if a transmission with error detection or error correction is desired. In this case, however, it is necessary to increase the number of steps in a channel or the number of channels in a frame, which options are not described further here.

The converter 12 receives the code words in clock e the main channels are transferred to the 6-digit main memory 13; in clock f there are 3 bits of this word to the output unit 14, from where it is transmitted during the clocks a ... c through line 15 to the receiver

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be transmitted. The first bit of the code word has meanwhile been transmitted to the control circuit 5 and indicates there whether it is a traffic sign (if it = "1") or an operating sign (if it is - "0"). In the first case, the 4th to 6th bit is transferred from the memory 13 to the output unit 14 during the following cycle c, in order to be put on the line from there during the cycles d ... f; in the second case this transfer does not take place. The control of the conditional transmissions is carried out by the control circuit in connection with the clock distributor 2 and the counter 3 for the signals of the main channels.

The same function as the input circuit 11 for the main channels fulfills for the additional channels the input circuit 21. Its inputs 7 (1) ... 7 (m) are with sources not shown in the additional channels characters to be transmitted connected. During the cycle time a, the character is transmitted to the information converter. The code word generated there is transferred to the additional memory 23 at the cycle time b, from where the Cycle time c each time one half of the code word to the output unit 14 and further during the cycle times d ... f transferred to line 15. These transmissions do not take place in every cycle time a, b and c. To tent c there is a Transfer of part of an additional code word from the additional memory 23 on the Aus ^ eeinheit 14 only if in

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Main memory 13 no traffic sign is stored, which can be seen from the fact that there is the first Bit is a "0".

The additional channel counter 4 is switched by half a step when in the code converter an operating signal occurs, be it on a main channel or on an additional channel. This counter controls together with the control circuit and the clock distributor 2 the transmissions a, b and c on the way the additional characters.

An example is given below for bits transmitted during channel times 5 to 9 at the same time with the respective position of the main channel counter 3 and of the additional channel counter 4.

Counter 3 Counter 4 110101 5 11 010110 6th 11 011111 7th 11 i 011011 8th 12th 010100 9 13th

The first digit in channel 5 is 1 and means that both step groups of the channel have a traffic sign of the main channel. The first digit in the

9098 44/0975 '-

BATH ORIGINAL

Channel 6 is O, so it is an operating sign, namely the operating sign /: the subscriber no. 6 has switched off his machine. The second group of steps is thus assigned to an additional channel, namely to the 11th additional channel after the counter has been set; Furthermore, since the counter stands on an integer, it forms the first part of a code word. This code word begins with 1, so it is a traffic sign, the second part of which comes into a main channel after the next traffic sign, namely in the second step group of the channel to 7. Likewise, the second step groups of channels 8 and 9 belong to additional channels that of the channel to 8 to the additional; channel 12; it forms a traffic sign because it starts with 0. Accordingly, the second step group of the channel 9 is the first part of a traffic sign of the additional channel 13. The counter is forwarded by half a step for each zero in the first digit of a code word. In addition to the synchronization of the main channels, the additional channels must also be synchronized in order to ensure their clear assignment in the sender and receiver. According to the block diagram of FIG. 1, the position of the counter 4 is transmitted as a code word in the channel η, specifically via the last line of the memory 11 and via the information converter 12 and the memory 13; however, some of these steps can also be skipped.

909844/0975

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Another possibility to synchronize the additional channels, which is not shown in the drawing, uses a certain additional channel instead of a main channel, in which the synchronization character 000 000 which cannot otherwise occur with the agreed characters.

FIG. 2 shows a block diagram for a receiver for receiving the signals from a transmitter according to FIG. 1 transmitted signals. The signals arrive on line 65, those with line 15 of the transmitter directly or is connected via transmission means. she is connected to the input of a synchronization circuit 51, which a clock signal t in the clock of the received Outputs step frequency and a frame signal that occurs once during a frame time. The clock signal is driving the clock distributor 52, which in each channel time again the Output signals a ... f, and the main channel counter 53, which supplies the channel signals 1 to η. The frame signal sets the clock distributor and main channel counter to their starting position, which means that synchronization takes place in the shortest possible time possible time.

The recording unit 64, which is connected to the input line 65, is controlled by the clock signal and stores the signals appearing in series on this and sends 3 bits each to the memory in groups

9 09 8 U / 09? δ - Λ, Γ,! Γλ?

BATH ORIGINAL

63 or 73. Of these, the first one takes the code words the main channels5 the second those of the additional channels. Both pass code words of 6 bits on to the information converter 62, which converts them into one for the operation of Teletyping machines suitable for start-stop operation Form converts and to the output unit 61 for the main channels or to the output unit 71 for the additional channels passes on, from where it is transferred to lines 56 (1) ... 56 (n-3) of the Haiiptkanäle or lines 57 (1) ... 57 (m) of the Additional channels are given.

In a similar way to being with the transmitter

all circuits by the clock signals a ... f emanating from the clock distributor 52 and by those from the control circuit 55 outgoing signals controlled. The signals are distributed to the corresponding storage units after setting the counter 53 for the characters of the haptic channels and the counter 54 for the additional channels.

Let there be three bits during the clocks a ... c

coming from the line in the recording unit 64 and, since these are certainly bits that belong to a signal in a main channel, are stored in the first three positions of the memory 63. The first bit is passed on from there to the control circuit and determines whether the next three bits received during the clocks d ... f are ₅ in the memory at clock time a

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or stored in memory 64. In the following cycle times b and c, the code word from 63 in the information converter 62 and passed on from there to the output unit 61.

Should a bit group from the acquisition unit 64 are given into the memory for additional channel characters 73, the position of the counter 54 determines the runs synchronously with the counter 4 in the transmitter, in which part of the memory 73 the storage is to take place. The ™ Counter 54, just like the counter, is incremented by every 0 that is on occurs first in a main or additional code word, shifted by half a step. Will that " Transmission of the synchronization signal for the additional counter as described above via an additional channel, so heard to him a similar frame synchronization circuit as for the divisor 53. If it is transmitted via the η-th Haujfck channel, this takes place after the η-th code word has been recorded its transmission directly from memory 63 to counter j either directly or via the code converter 62. The transmission consists in setting the counter to the position indicated by the code word. In general he is already in this position; however, a transmission error should occur during the last frame the counter at the end of the frame is set to the correct position without further ado, unless that the synchronization has fallen out of step or that an error has just occurred during the transmission of the counter position

909844/0975

was done. - '

BATHROOM ORIGINAL - 16 -

Within the scope of the invention, others can also Code words than those described can be used, there can also be a different number of steps per channel and others Changes are made.

In particular, the method can also be used for the transmission of telephony according to the PCM method (PCM = pulse code modulation). In this case the lines 6 (1) ... and 7 (1) ... carry telephone signals which are sampled in the input circuits 11. The scanning results are transmitted as voltage values to the information converter 12, which in this case is an analog-to-digital converter. Instead of the sign <there is , for example, a sign that the subscriber in question has hung up, and the sign β is replaced by a sign that a pause in the conversation has occurred. The remaining parts of the transmitter are unchanged; Of course, the number of bits per channel and the step speed must be adapted to the requirements. The units corresponding to the transmitter are also to be used in the receiver. In particular, the information converter 62 is a digital-to-analog converter.

Expectations :

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Claims (7)

1537U6 claims 1. Method for the transmission of signals over several transmission channels in digital form a "connection path, with the transmission time in equally long frame times and these are divided into channel times, and each specific channel times are permanently assigned to certain transmission channels, characterized in that a plurality of seldom transmitted signals as code words with a number of steps equal to the number of steps of a channel time and a minority of frequently transmitted signals as code words are transmitted with a lower number of steps and that the transmission of the short code words unused channel time segments are used to transmit the code words of additional channels, which no specific channel times are allocated. 2. The method according to claim 1, characterized in that the steps of a channel time in step groups are divided and that each of the short code words is assigned a smaller number of step groups is as a long code word. BATH ORIGINAL " 909844/0975 -ie- 1537H6 3. The method according to claim 2, characterized in that the first step group of each code word contains an identifier that shows whether it is a short or a long code word. 4. The method according to claim 1, characterized in that the long code words for transmission the messages sent by the sources are used, while the short code words indicate the state or a of the states of the source in which no messages are transmitted. 5. Transmission system for performing the method according to claim 1, consisting of transmitter, transmission ■ transmission means and receiver, the transmitter including input circuitry that receives signals on a plurality of from lines and to an information converter passes on, which converts each signal into a digital code word suitable for rhythmic transmission, furthermore 'an output unit that receives the information from the information converter The code words received are supplied to the transmission means in a form suitable for this, and the receiver a receiving circuit with synchronization means for Contains step and frame synchronization, also a recording unit controlled by this, which the messages receives from the transmission means and passes it on to an information converter, and an output circuit that the 9 09 8 M / 0 976. " ¹⁹ - BATH 1537H6 Signals from the information converter takes over and in the original form on a plurality of Outputs lines, characterized in that the transmitter and receiver each contain a memory, the one between the information converter and the output unit or between the receiving unit and the information converter is that the input circuit, output circuit and memory each consist of two parts, one of which each of the main channels, the second of which is assigned to the additional channels, that sender and receiver each contains an additional channel counter, which in each case with a short code word in any channel half a step further, and that the transmitter and receiver contain control circuits, which cause the transmission of characters on the additional channels indicated by the counter. 6. Transmission system according to claim 5, characterized by means in the transmitter which transmit the ' Carrying of the position of the additional counter in the transmitter characterizing code word during a certain Initiate channel time and by means in the receiver, which the position of the additional reception counter set to the position indicated by the transmitted code word. 909844/0 97 5 .. "" ORIGINAL BATHROOM - .20-1537K6 7. Transmission system according to claim 5, characterized by means in the transmitter which the Initiate transmission of a unique synchronization character in a specific additional channel and means in the receiver which, when the synchronization character is received, the additional counter to the Bring the position assigned to the specific additional channel. PAe Dr Andrejewski, Dr Honke Bath ^ 909844/0975 - 2 ° Iü ■■ --- ■
67. ' 7/30/7?